This invention relates to a folding portable (or hand-held) device that has upper and lower units coupled to each other with a hinge mechanism having a folding/unfolding axis and a rotating axis perpendicular to the folding/unfolding axis. Particularly, this invention relates to a wiring structure used in the folding portable device together with the hinge mechanism.
Recently, most of mobile phones have various additive functions, such as a browser, a mailer, a personal information scheduler and the like. The mobile phone is increasingly becoming sophisticated as a portable information terminal. Accordingly, a larger display for the mobile phone is required to display letters, characters (or ideographs), numerals, a static image(s) and/or a moving image(s). Meanwhile, there is a demand for weight saving and miniaturizing of the mobile phone.
Employing a folding structure can meet the above-mentioned incompatible demands in a measure. An existing folding mobile phone comprises upper and lower units and a hinge mechanism which couples the units to each other. In the existing folding mobile phone, a display is provide in the upper unit while a key set is provided in the lower unit. The display and the key set come close to each other, as the upper and the lower units are unfolded by means of the hinge mechanism. When the upper and the lower units are completely unfolded, the display and the key set are hidden by them.
A certain type (hereinafter referred to as a rotatable type) of the existing folding mobile phone can expose the display even when the upper and the lower units are completely folded. This is accomplished by, for example, using a ball joint as the hinge mechanism. The ball joint enables the upper unit to be rotated with respect to the lower unit. The rotatable type folding mobile phone allows a user to use the browser, the mailer or the like when the upper and the lower units are folded. Such a rotatable folding mobile phone is disclosed in Japanese Unexamined Patent Publication (JP-A) No. Tokkaihei 11-215218.
Now, a serious matter is a wiring structure between the upper unit and the lower unit of the rotatable folding mobile phone. That is, the wiring structure must have durability and a smaller size. However, the above mentioned document does not teach or suggested about the wiring structure.
Additionally, a personal information terminal employing a structure like the rotatable folding mobile phone needs a manner to allow of compact housing of signal lines, which amount to dozens or about a hundred.